Error in KE27 - run for trading goods

Question

Dear gurus!
i have a error when i run KE27.
Current, my customer don't have production activity. In SAP system, we activated Material Ledger. in period, i wanna run Periodic valuation (KE27) for all trading goods. (Note that we don't have finished good because not have production, customer just sell trading goods)
I configured some steps follow:
1. Define and Assign Valuation Strategy (in this step, i wonder that which valuation strategy is user for valuation for trading goods)
- valuation trategy : 001
- sequence     material costing       quantity field
       10                        x                            VV099
- assignment of valuation strategy
point of valuation                   record type              valuation strategy
    02                                              F                               001
2. Define Access to Actual Costing/Material Ledger
   Costing key -  01
  0 legal valuation
  1. only trasfer total  cost
   periodic a/c line item
3. Assign Costing Keys to Material Types
point of valuation           record type    Material type        Valid to         costing key 1
        02                                   F                 HAWA              31.12.9999       01
Then, after run period closing in Material ledger, i run KE27 to periodic valuation , but system get error:
" Message no. KE435 - Costing key 01 does not exist
In Profitability Analysis, the system tried to valuate by reading a product cost estimate. The Customizing settings in CO-PA call for valuation using costing key 01.
This costing key is not defined "
explicitly, i maintained costing key and assigned this to trading goods - material type.
Please, help to fix it!
any idea is appreciated.

Answer 1

Activating ML is necessary because in my customer's company sell goods at planed price then revaluate value of inventories and COGS at actual price in the end of each of period. So we decide to use standard price control for trading goods and active Material ledger.
end of period, we run period procedure of ML for trading goods, we expect allocation different amount, revaluate inventories and consumption. Run revaluation step of costing run in ML, we revaluate all   ending inventories and consumption transaction except billing transaction. So, we think that we need to run Ke27 to revaluate all line item document in COPA from billing.
so anybody to help me revaluate consumption amount from billing at actual price in end of period?
thanks in advance!